The 74FCT257T is a high-speed quad 2-input multiplexer. The 74FCT257T has a common Output Enable (OE) input. When OE is high, all outputs are switched to a high-impedance state allowing the outputs to interface directly with bus-oriented systems. The 74FCT257T operates at -40C to +85C


  • A, C, and D speeds
  • Low input and output leakage ?1 uA (max.)
  • CMOS power levels
  • True TTL input and output compatibility: – VOH = 3.3V (typ.) – VOL = 0.3V (typ.)
  • High Drive outputs (-15mA IOH, 48mA IOL)
  • Meets or exceeds JEDEC standard 18 specifications
  • Power off disable outputs permit "live insertion"
  • Available in 16 pin QSOP package

Product Options

Orderable Part ID Part Status Pkg. Type Lead Count (#) Temp. Grade Pb (Lead) Free Carrier Type Buy Sample
Obsolete QSOP 16 C Yes Tube
Obsolete QSOP 16 C Yes Reel
Obsolete QSOP 16 C Yes Tube
Obsolete QSOP 16 C Yes Reel
Obsolete QSOP 16 C Yes Tube
Obsolete QSOP 16 C Yes Reel

Documentation & Downloads

Title Other Languages Type Format File Size Date
Datasheets & Errata
74FCT257T Datasheet Datasheet PDF 174 KB
Application Notes & White Papers
AN-154: Estimating Power Dissipation in CMOS Application Note PDF 80 KB
AN-152: FCT-T Octal Logic Characteristics... Application Note PDF 143 KB
AN-147: The Myth of Ground Bounce Measurements Application Note PDF 130 KB
PDN# : CQ-15-04 Quarterly Market Declined PDN Product Discontinuation Notice PDF 545 KB
PCN#: A-0410-02, Change IDT marking logo with new IDT gridless w Product Change Notice PDF 24 KB
PCN# A-0508-02: OSET Alternate Assembly Location for Green Product Change Notice PDF 18 KB
PCN#A-0504-02R1: Assembly Transfer IDT-Manila to OSE-Ph Product Change Notice PDF 16 KB
PCN#: TB-0504-01, Transfer Test & Backend from IDT-Manila to IDT Product Change Notice PDF 35 KB
PCN#: A-0412-04 - To comply with Pb-free labels - Green Products Product Change Notice PDF 80 KB
PCN#:A-0309-06 Rev1, Hermetic transfer to ATP-P1 Product Change Notice PDF 44 KB
PCN # L0203-09R2 Addendum Fab Transfer from Fab 2 to Fab 4 Product Change Notice PDF 101 KB
PCN#:A-0401-01, new m/c G600 & 8290 d/a material Product Change Notice PDF 196 KB
PCN#:A-0312-01, new mold compound material - G600 Product Change Notice PDF 109 KB
PCN#:A-0312-02, new die attach material - 8290 Product Change Notice PDF 116 KB
PCN#: A-0310-01, Green Products Product Change Notice PDF 26 KB
PCN# L0203-09R1 Tech Upgrade & Fab Transfer Product Change Notice PDF 98 KB
PCN# G-0203-05 Mold Compound Product Change Notice PDF 40 KB
PCN# G0106-01, Moisture Sensitive Label Change Product Change Notice PDF 274 KB
PDN# Logic-01-04: Obsolescence Notice Product Discontinuation Notice PDF 41 KB
PDN# Logic-00-07: Obsolete Selective Speed Grades Product Delete Notice PDF 14 KB
PDN# Logic-00-09: Obsolete PDIP Package Product Discontinuation Notice PDF 73 KB
PCN# G0005-01, Laser Top Mark Product Change Notice PDF 24 KB
74FCT257T Hspice Model Model - HSPICE ZIP 18 KB
74FCT257T IBIS Model Model - IBIS ZIP 8 KB
PDN# L_05_01: Obsolescence Notice ALL PDF 130 KB